Detection of an anatoxin-a(s)-like anticholinesterase in natural blooms and cultures of cyanobacteria/blue-green algae from Danish lakes and in the stomach contents of poisoned birds

Ten natural bloom samples of cyanobacteria from the Danish lakes Knud s? (5), Ravn s? (4), and Salten Langs? (1) collected during 1993-1995 were assayed for toxicity by mouse bioassay, for acetylcholinesterase inhibiting activity by a colorimetric method, and for microcystins by enzyme-linked immunosorbent assay. In the mouse bioassay, seven samples were neurotoxic, two were non-toxic and one gave a protracted toxic response. One of the non-toxic and the single protracted toxic sample both contained anticholinesterase activity equivalent to 4 micrograms anatoxin-a(s) g-1. The neurotoxic samples contained equivalents to 20-3300 micrograms anatoxin-a(s) g-1. The highest anticholinesterase activities (equivalent to 2300 and 3300 micrograms anatoxin-a(s) g-1, respectively) were found in samples collected from Lake Knud s? in connection with bird-kills in 1993 and 1994. Small amounts of microcystins (0.1-0.9 microgram g-1) were detected in all samples but one. All Lake Knud s? and Lake Ravn s? samples were dominated by Anabaena lemmermannii, and the Lake Salten Langs? sample by several species of Anabaena. Gel filtration profiles indicated similarity between the toxic component from the Lake Knud s? 1994 bloom with registered bird-kills and anatoxin-a(s) isolated from Anabaena flos-aquae NRC-525-17. Anticholinesterase-producing cultures of A. lemmermannii were isolated from the Lake Knud s? 1993 bloom. These laboratory cultures produced anatoxin-a(s) equivalents of 29-743 micrograms g-1. Other cultures of A. lemmermannii isolated from Lake Knud s? and Lake Ravn s? were hepatotoxic or non-toxic. Dead birds collected from Lake Knud s? during the neurotoxic 1993 Anabaena bloom possibly died from cyanobacterial toxicosis. The stomach contents contained colonies and single trichomes of Anabaena, and anticholinesterase activities equivalent to 2.1-89.7 micrograms anatoxin-a(s) kg-1 body weight and microcystins (53-95 ng kg-1) were also detected.     

Susceptibility of three laboratory strains of Aedes albopictus (Diptera: Culicidae) to Japanese encephalitis virus from Taiwan

An 11-year-old boy developed florid reactive periostitis several years after minor trauma. The symptoms responded initially to antibiotics, but after cessation, rapidly recurred and progressed, requiring a ray amputation to relieve the pain and to achieve a functional hand. The reactive periostitis affected the volar aspect of two adjacent phalanges with sparing of the intervening joint, confirming that this is a reactive process rather than a benign neoplasm.     

武汉市2010年志贺氏菌菌株情况分析

目的 掌握武汉市2010年细菌性痢疾监测中分离的志贺氏菌的生化血清学分型、药物敏感状况及毒力基因携带情况.方法 按<全国细菌性痢疾监测方案>提供的方法进行病原菌分离鉴定和药敏试验;利用PCR方法分别对志贺氏菌分离株7对毒力相关基因进行检测.结果 2010年分离志贺氏菌15株,宋内氏菌12株,福氏志贺氏菌3株.志贺氏菌敏感药物为阿莫西林(66.7%),诺氟沙星(73.3%)、环丙沙星(60.0%).全部耐药的有利福平,氨苄两林、萘啶酸.所有菌株对11种抗生素中的6种及以上耐药.15株菌株ipaH基因检出率为100%,ial,virA及sell基因的检出率均为73.3%.setlA与setlB基因仅在福氏志贺氏菌检出.结论 2010年武汉市细菌性疾病病原菌以宋内氏志贺菌为主,耐药情况有口趋严重的趋势,毒力基冈携带模式相对单一.     

An experimental study of natural convection and wall effect in liquid metals contained in vertical cylinders

Experimental results are presented giving Nusselt Number as a function of Rayleigh Number for liquid mercury and lead when submitted to an upward temperature gradient in a cylindrical vessel. The wall effects have been evaluated by using containers with different height to diameter ratios. For values of Ra ranging from 2.10⁴ to 2.10⁷, Nu may be determined by the relationship: (Nu±12%)=0.078 (0.68) ^L/D Ra^1/3 the region in the neighborhood of Ra=10⁴ is characterized by a wide dispersion of data points which has been attributed to the transition from laminar to turbulent regime. The extension of these results to a wide variety of metallurgical problems is discussed.     

Biliary excretion of biochemically active cyanobacteria (blue-green algae) hepatotoxins in fish

Previous reports demonstrated that microcystin and related cyanobacteria polypeptides are rapidly cleared from plasma and accumulate in liver tissue. In the present study, we have used their ability to inhibit protein phosphatases to show that these cyanobacteria hepatotoxins are excreted into the bile of experimentally poisoned rainbow trout. At various times after oral administration of hepatotoxic Microcystis aeruginosa, bile samples were analysed for microcystin content by methanol extraction and protein phosphatase assays. An inhibitory principle that specifically suppressed protein phosphatase activity was detected in all bile samples removed between 1 and 72 h after oral exposure to toxic algae. These results indicate that biochemically active microcystin molecules are excreted into the biliary tract of poisoned fish.     

Enzymatic variability in natural populations of Aedes aegypti (Diptera:Culicidae) from Brazil

Yellowfever mosquitoes, Aedes aegypti (L), were collected from 3 towns located within 70 km of each other in the State of Sao Paulo to evaluate the protein variability of natural populations. Electrophoretic analysis permitted the identification of 6 loci responsible for the production of leucine aminopeptidase, 3 for esterases and malic enzyme, 2 for malate dehydrogenase, isocitrate dehydrogenase and alpha-glycerophosphate dehydrogenase, and 1 for phosphoglucomutase. For the 3 populations, the range for alleles per locus (1.63-2.03), the proportion of polymorphic loci (37.5-50.0%), and the expected mean heterozygosity (0.48-0.53) were greater than reported for other populations of A. aegypti. Although the 3 populations were similar genetically, the 1.8% differentiation was significant.     

Immunological study of Japanese encephalitis virus--serological analysis of strains isolated from Thailand, India, Singapore and Taiwan

Antigenic comparison of the twenty-two Japanese encephalitis (JE) virus strains, which were isolated from Taiwan, Singapore, Thailand and India between 1963 and 1984, was carried out by the hemagglutination inhibition (HI) test using the 15 monoclonal antibodies characterized by the different reactivities against Nakayama-RFVL, Beijing 1, Kamiyama, Muar or 691004 strain. Of these twenty-two strains, the seventeen strains reacted with the Kamiyama type-specific monoclonal antibody (KAMIMA 6), but anti-Nakayama, anti-Beijing 1 and anti-Muar type-specific antibodies showed no reactivities with any of the strains. This suggested that the currently prevalent JE virus strains in these areas belonged to the Kamiyama serotype. The other five strains (ThCMP 1982, KE083, KE093, 733913 and Ling) did not react with the above four type-specific monoclonal antibodies. Of these five strains, however, all except the KE093 strain showed a similar pattern to the Kamiyama strain on the basis of the HI reactivities against the other eleven antibodies. The KE093 isolated from Thailand in 1983 showed immunologically outstanding different from the other strains. This result showed the immunological diversity of the JE virus.     

Isolation of cytopathic small round virus (Aichi virus) from Pakistani children and Japanese travelers from Southeast Asia

Aichi virus was isolated in Vero cells from 5 (2.3%) of 222 Pakistani children with gastroenteritis but none was found in 91 healthy children. Aichi virus was also isolated from 5 (0.7%) of 722 Japanese travelers returned from tours to Southeast Asian countries and complained of gastrointestinal symptoms at the quarantine station of Nagoya International Airport in Japan. Of 5 Japanese travelers, 3 were returning from Indonesia, and 2 from Thailand or Malaysia. These results indicate that Aichi virus or a similar agent is endemic in Southeast Asian countries and is a cause of gastrointestinal symptoms in children in these areas or in Japanese travelers who visit there.     

Reproduction of progressive retinal degeneration (bright blindness) in sheep by administration of ptaquiloside contained in bracken

The process of occurrence of bright blindness, progressive retinal degeneration (PRD), in sheep was observed using two Suffolk ram lambs fed on a diet containing bracken powder. The first sign of the bright blindness was detected 4 months after the start of experiment. Based on these preliminary results, the amount of bracken powder necessary to induce PRD was estimated (experiment I). In the following experiment, ptaquiloside (PT), a norsesquiterpene glucoside of the illudane type isolated from bracken, which is a bracken carcinogen and a causative principle of cattle bracken poisoning was administered to two Suffolk ram lambs. It was clearly demonstrated in this experiment (experiment II) that PT present in bracken is also a causative principle of PRD.     

The tumor suppression function of p21Waf is contained in its N-terminal half ('half-WAF')

The Waf-1 encoded protein, p21, mediates p53 suppression of tumor cell growth. Overexpression of p21 in the H1299 tumor cell line suppresses colony formation similar to that resulted from p53 overexpression. In an effort to localize the tumor suppression function within the structure of p21 we utilized vectors constructed with systematic truncations of p21 and tested their efficiency in suppressing tumor cell growth. We demonstrate that the N-terminal half of the p21 molecule (residues 1-80 and 1-89) shows better tumor cell growth suppression than the entire p21 molecule whereas the C-terminal half of p21 does not show this effect. These results may have implications for gene therapy of cancer.     

Estimation of the cytogenetic homeostasis in natural populations of small murine rodents from the Lower (Astrakhan') and Middle (Chapaevsk) Volga regions

Frequencies of chromosomal aberrations were estimated in the bone marrow of two background small rodent species, the bank vole (Clethrionomys glareolus) and the house mouse (Mus musculus) from the middle (Chapaevsk, Samarskaya oblast) and lower (Astrakhanskaya oblast) Volga regions. The majority of chromosomal aberrations were chromatid deletions. In the studied species, cytogenetic disturbances were most prevalent in areas where the anthropogenic environmental pollution was maximum. The lowest frequencies of disturbances were observed in the control areas, where the environmental pollution was insignificant. Thus, anthropogenic exposure caused disturbances of cytogenetic homeostasis in different small rodents living in different regions.     

The analgesic activity of crotamine, a neurotoxin from Crotalus durissus terrificus (South American rattlesnake) venom: a biochemical and pharmacological study

Crotamine, a 4.88 kDa neurotoxic protein, has been purified to apparent homogeneity from Crotalus durissus venom by gel filtration on Sephadex G-75. When injected (i.p. or s.c.) in adult male Swiss mice (20-25 g), it induced a time-dose dependent analgesic effect which was inhibited by naloxone, thus suggesting an opioid action mechanism. When compared with morphine (4 mg/kg), crotamine, even in extremely low doses (133.4 microg/kg, i.p., about 0.4% of a LD50 is approximately 30-fold more potent than morphine (w/w) as an analgesic. On a molar basis it is more than 500-fold more potent than morphine. It is also much more potent than the lower molecular weight crude fractions of the same venom. The antinociceptive effects of crotamine and morphine were assayed by the hot plate test and by the acetic acid-induced writhing method. Therefore, both central and peripheral mechanisms should be involved. Histopathological analysis of the brain, liver, skeletal muscles, stomach, lungs, spleen, heart, kidneys and small intestine of the crotamine injected mice did not show any visible lesion in any of these organs by light microscopy. Since crotamine accounted for 22% (w/w) of the desiccated venom, it was identified as its major antinociceptive low molecular weight peptide component.     

甘肃省2006-2009年细菌性痢疾耐药谱及脉冲场凝胶电泳分析

目的 对中国甘肃省2006-2009年细菌性痢疾监测点分离到的志贺菌进行耐药谱和脉冲场凝胶电泳(PFGE)分子分型研究,探讨甘肃省细菌性痢疾的分子流行病学特征.方法 对2006-2009年甘肃省细菌性痢疾监测点分离到的473株志贺菌进行血清型及耐药性分析;采用限制性内切酶对2009年分离的166株志贺菌进行PFGE分型分析.结果 福氏志贺菌为甘肃省2006-2009年优势血清群;Fxv血清型为福氏志贺菌优势血清型(占44.5%),其次为2a血清型(占33.1%);福氏志贺菌和宋内志贺菌普遍对氨苄西林、四环素和利福平耐药,耐药率在90.3%～100%之间;不同血清型(群)间耐药率有差异;PFGE分析发现CN0200为福氏志贺菌主要PFGE带型(占47.8%);相同血清型具有相似带型,归于同一簇.结论 阐明了甘肃省细菌性痢疾的流行血清群为福氏志贺菌,血清型主要为FXV和2a.福氏和宋内志贺菌普遍对氨苄西林、四环素和利福平耐药.     

Brain uptake of S-(1,2-dichlorovinyl)glutathione and S-(1,2-dichlorovinyl)-L-cysteine, the glutathione and cysteine S-conjugates of the neurotoxin dichloroacetylene

Dichloroacetylene causes trigeminal neuropathy in humans and animals. Glutathione conjugation of dichloroacetylene affords S-(1,2-dichlorovinyl)glutathione (DCVG), which is hydrolyzed to S-(1,2-dichlorovinyl)-L-cysteine (DCVC). This study was undertaken to test the hypothesis that the neurotoxicity of dichloroacetylene may be associated with glutathione S-conjugate formation and brain uptake and bioactivation of the dichloroacetylene-derived S-conjugates. With the Oldendorf technique, the Brain Uptake Index for [35S]DCVC and [35S]DCVG was determined and compared with the uptake of [35S]methionine and [14C]sucrose. Brain uptake of DCVC exceeded uptake of methionine and DCVG uptake was comparable to methionine uptake. Both [35S]DCVC and [35S]DCVG were recovered intact in brain tissue. The uptake of the 35S-labeled S-conjugates was inhibited by unlabeled DCVC and DCVG in a concentration-dependent manner. The data indicated that DCVC, but not DCVG, was transported by the sodium-independent system-L transporter for neutral amino acids. In vitro studies revealed that DCVG can be hydrolyzed to DCVC by brain tissue in a concentration-dependent manner.     

Occurrence of extended spectrum beta-lactamases (ESBL) and inducible beta-lactamases (IBL) in clinical strains of gram-negative rods

Hairy cell leukemia (HCL) is clinically associated with severe T-cell dysfunction. Several new observations have given more insight into the abnormal T-cell responses seen in this disease. T-lymphocytes in the spleen of patients with HCL seem to be abnormally activated. On the other hand, they are non-responsive, possibly as a result of monocytopenia which may lead to inadequate antigen presentation. This, together with the lack of CD28 on T-cells, may cause T-cell dysfunction. Furthermore, there is a very restricted repertoire of the T-cell receptor-beta family, which may also result in non-responsiveness. Otherwise, T-cell clonal excess may be indicative for activated, possibly autoreactive T-cells.     

Differentiation of natural red wines from white wines blended with oenocyanine (author''s transl)

A method is proposed for the differentiation of natural red wines from those obtained by addition of oenocyanine to white wines. The procedure is based on the determination of tannin phenolics and nontannin phenolics by selective precipitation with methyl cellulose and subsequent estimation of the intensity of absorption at 450 nm and 520 nm. The sum of ratio: mg/1 non tannin phenolics/absorption at 450 nm X 1000 and mg/1 tannin phenolics/absorption at 520 nm X 1000, furnishes values which are in correlation with the origin of two wines and such as to consent their differentiation.